C语言获取本机Mac地址的代码

//linux  int GetLocalMacAddr(char *szMac,int *pnMacLen)  {    int   sock;      struct   sockaddr_in   sin;      struct   sockaddr   sa;      struct   ifreq   ifr;      unsigned   char   mac[6];             sock=socket(AF_INET,SOCK_DGRAM,0);      if (sock==-1)      {        perror("socket");        return 1;      }             strncpy(ifr.ifr_name,"eth0",sizeof(ifr.ifr_name));      ifr.ifr_name[IFNAMSIZ-1]   =   0;             memset(mac,0,sizeof(mac));      if (ioctl(sock,SIOCGIFHWADDR,&ifr)< 0)      {        perror("ioctl");        return 2;      }             memcpy(&sa,&ifr.ifr_addr,sizeof(sin));      memcpy(mac,sa.sa_data,sizeof(mac));      char curmacstr[64];    memset(curmacstr,0,sizeof(curmacstr));    //sprintf(curmacstr,"%.2X-%.2X-%.2X-%.2X-%.2X-%.2X",mac[0],mac[1],mac[2],mac[3],mac[4],mac[5]);    sprintf(curmacstr,"%.2X:%.2X:%.2X:%.2X:%.2X:%.2X",mac[0],mac[1],mac[2],mac[3],mac[4],mac[5]);    strcpy(szMac,curmacstr);    return 0;     }     // windows  int CUtil::GetOtherMacAddr(char *szIP,char *szBuf,int *pnBufLen)  {      HRESULT hr;      IPAddr  ipAddr;      ULONG   pulMac[2];      ULONG   ulLen;      char strMacAddr[100]={0};      ipAddr = inet_addr (szIP);      memset (pulMac, 0xff, sizeof (pulMac));      ulLen = 6;      hr = SendARP (ipAddr, 0, pulMac, &ulLen);      if(hr!=NO_ERROR)          return 1;         unsigned char * mac_addr=(unsigned char*)pulMac;      //sprintf(strMacAddr,"%02X-%02X-%02X-%02X-%02X-%02X",mac_addr[0],mac_addr[1],      //    mac_addr[2],mac_addr[3],mac_addr[4],mac_addr[5]);      sprintf(strMacAddr,"%02X:%02X:%02X:%02X:%02X:%02X",mac_addr[0],mac_addr[1],          mac_addr[2],mac_addr[3],mac_addr[4],mac_addr[5]);      if ( *pnBufLen <= (int)strlen(strMacAddr) )          return 2;      strcpy(szBuf,strMacAddr);      *pnBufLen = strlen(szBuf);         return 0;  }     int CUtil::GetLocalMacAddr(char *szMac,int *pnMacLen,char *szIP /*=NULL */)  {      //如果指定了IP，则直接按IP获取MAC      //否则，需要先获取本机名称，再获取IP，再获取MAC      if ( szIP != NULL )          return GetOtherMacAddr(szIP,szMac,pnMacLen);         char szHostName[256] = {0};      int nRet = gethostname(szHostName,256);      if ( nRet == SOCKET_ERROR )          return 1;         //获取本机名称      struct hostent* hHost = gethostbyname(szHostName);      if ( hHost == NULL ||  hHost->h_addr_list[0] == NULL )          return 2;         //获取IP地址      memset(szHostName,0,256);      strcpy(szHostName,inet_ntoa(*(struct in_addr *)hHost->h_addr_list[0]));         //获取MAC      return  GetOtherMacAddr(szHostName,szMac,pnMacLen);  }